This invention relates generally to thrust bearings with rolling elements and, more particularly, to rolling element thrust bearings with anti-reversal features.
Thrust bearings with rolling elements are in general use in transmissions and similar devices to support axial loads between components. For example, such thrust bearings are used in automotive torque converters to position and support a stator. To function correctly, the thrust bearing must be oriented with a specific face against the stator or other housing. Typically, such thrust bearings are painted with a stripe to indicate the face of the thrust bearing that is to face outward from the stator or other housing, and the thrust bearing is placed into a recess of the housing.
Some thrust bearings have been equipped with anti-reversal tabs that extend so as to interfere with the recess in the housing and prevent inadvertent installation of the thrust bearing when in a reversed orientation. However, with anti-reversal tabs that are turned radially outward, problems have occurred when a stack height checking machine applied a programmed load, breaking the tab. And, with anti-reversal tabs that are turned radially inward, so as to interfere with a shaft or other piloting surface, catastrophic failures have occurred due to out of roundness and inner retainer wear.
The foregoing illustrates limitations known to exist in present devices and methods.
Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.
In one aspect of the invention, this is accomplished by providing a thrust bearing comprising a plurality of rollers retained within a bearing cage, the rollers being aligned radially with respect to an axis of the bearing cage, and a first thrust washer concentric with the bearing cage. The first thrust washer has a flat raceway portion for rolling contact of the rollers and a curled portion that wraps around a portion of the bearing cage to retain the bearing cage and the first thrust washer together as an assembly. The curled portion includes a rim that extends radially 360 degrees with respect to the axis and has a folded configuration such that a doubled portion is offset with respect to an axial midpoint of the thrust bearing to prevent the thrust bearing from being installed with a reversed orientation.
The foregoing and other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing figures.